Vascular Endothelial Growing Factor (VEGF) takes part in the vascular and cerebral regeneration in the neurological system. It is considered a neuronal protector. Cerebral hypoxia stimulates the expression of VEGF for starting the vascular neogenesis. No studies related VEGF with delirium in the critical patient. Assuming that hypoxia and ischemia can develop delirium in the ICU, the VEGF levels may be augmented.